Electrode harness and method of taking biopotential measurements

ABSTRACT

The present invention relates to an electrode harness and more particularly to an electrode harness with various features, which enhance the use and performance of the electrode harness. The present invention further relates to a method of taking biopotential measurements. The electrode harness and methods of the present invention allow for use with most applications where biopotential measurements are taken. The electrode harness can be used in ECG (or EKG), EEG, EMG, and other such biopotential measurement applications. Because of the versatility of various embodiments of the present invention, preferably the electrode harness can be adjusted for different applications or for application to various sized and shaped subjects. The electrode harness is further preferably part of a system, which includes either wireless or tethered bridges between the electrode harness and a monitor, and preferably includes various forms of processors for analyzing the biopotential signal.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional patent application of U.S. patent application Ser.No. 10/988,358 filed on Nov. 12, 2004.

The U.S. Government has a paid-up license in this invention and theright in limited circumstances to require the patent owner to licenseothers on reasonable terms provided for by the terms of contract numberDMI-0216284 awarded by the National Science Foundation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrode harness and moreparticularly to an electrode harness with various features, whichenhance the use and performance of the electrode harness. The presentinvention further relates to a method of taking biopotentialmeasurements.

2. Technical Background

Medical diagnostics include many tests that obtain biopotentialmeasurements from the surface or just under the surface of the skin of asubject. These tests vary widely, ranging from the electro-cardiogram(EKG) that measures electric impulses generated by the heart, to theelectroencephalogram (EEG) which measures electric impulses generated bythe brain. These diagnostics, and a multitude of others, requireelectrodes to be placed on the skin of a subject (statement about EMG).These electrodes, which routinely measure weak signals 100 microvolts orless for (EEG), must be very sensitive to accurately pick up such smallsignals. In addition, these electrodes are very sensitive to placementand contact with the subject's skin. Most biopotential monitoringsystems today, generally speaking, require many different components,pieces, and operations to use. The more complicated these systems arethe more time and manpower is required to operate and utilize them, andthe greater the risk of inaccurate measurements.

More recently, electrode harnesses have been developed to integrate theplacement of electrodes for various medical applications. The electrodeharnesses, however, are simple and have not been very effective givenmost are difficult to use, and attempt to integrate existing electrodetechnology into their design. An example of this type of device isdescribed in Jones et al. U.S. Pat. No. 4,595,013. Jones et al.describes an electrode harness wherein a plurality of electrodes arepermanently mounted on a flexible adhesive-backed harness pad. Anotherexample is described in U.S. Pat. No. 4,854,323 to Rubin wherein anelectrode harness is described having a hollow tub for containing andhousing the individual lead wires for each electrode and a flexiblestylet which when bent, into a desired shape, will maintain that shapeuntil reshaped. The individual electrodes are slideably adjustable aboutthe exterior of the hollow tube to enhance a more precise positioning ofthe electrodes to maximize the recording of ECG information from asubject. This electrode harness requires a downward biased weight of theelectrode carrying tube to enhance the attachment and therefore signalfrom the electrode. Finally, another example is described in U.S. Pat.No. 6,611,705 to Hopman et al. Hopman et al. describes the use of an ECGelectrode connector with a plurality of expandable arms interconnectedwith the electrodes and each of the expandable arms having releasableconnectors.

The electrode harnesses that have been developed suffer from one or moreof the following drawbacks. None of the electrode harnesses developeduse standard gel type electrodes, wherein once attached or connected,the electrodes cannot be released. Therefore, once used with theseconnectable electrodes the existing electrode harnesses cannot bedisposed of in one piece along with the harness since the electrode maybecome separated from the harness. Another drawback is none of theelectrode harnesses contain an adjustable connection point for theelectrodes to allow for the harness to be adapted to either differentsized subjects or different applications. Still another drawback is noneof the electrode harnesses electrically shield the electrodes from largedefibrillator voltages. Still yet another drawback is that none of theelectrode harnesses contains trimable electrodes or electricalconnections so the electrode harness can be personally modified for aparticular subject or application. Finally, none of the electrodeharnesses contain a dry electrode, which can be used to enhance reducethe complexity, and variability of the measurement system and theelectrode site preparation prior to application. “Dry” electrodesrequire no skin preparation or conductive gel. (with adhesive andwithout adhesives contained on the harness/and electrode)

In view of the foregoing drawbacks, it is the object of the presentinvention to develop an electrode harness, which overcomes one or moreof these drawbacks. More specifically, it would be desirable to have anelectrode harness with non-releasable connectors. Additionally, it isthe object of the present invention to develop an electrode harness withan adjustable electrode connection point. Further, it is the object ofthe present invention to have an electrode harness which is shieldedfrom large defibrillator voltages. Still further, it is the object ofthe present invention to develop an electrode harness that containstrimable electrodes or electrical connections. Finally, it is the objectof the present invention to have an electrode harness containing dryelectrodes.

SUMMARY OF THE INVENTION

The present invention relates to an electrode harness and moreparticularly to an electrode harness with various features, whichenhance the use and performance of the electrode harness. The presentinvention further relates to a method of taking biopotentialmeasurements.

The electrode harness' and methods of the present invention allow foruse with most applications where biopotential measurements are taken.The electrode harness' can be used in ECG (or EKG), EEG, EMG, and othersuch biopotential measurement applications. Because of the versatilityof various embodiments of the present invention, preferably theelectrode harness can be adjusted for different applications or forapplication to various sized and shaped subjects. The electrode harnessis further preferably part of a system, which includes either wirelessor tethered bridges between the electrode harness and a monitor, andpreferably includes various forms of processors for analyzing thebiopotential signal.

The electrode harness of the present invention overcomes one or more ofthe significant drawbacks of other electrode systems. One of thefeatures of various embodiments of the present invention includes aharness with lockable or non-releasable connectors, which allows fordisposal or removal of the electrode harness and electrodes in one piece(application of harness and electrodes while maintaining the connection:i.e doesn't fall off or lose electrical connect once inserted. Thisprevents clutter and more importantly medical waste by reducing thepossibility that the electrodes separate from the harness. Anotherfeature of the electrode harness of the present invention is the use ofan adjustable connection point. More specifically, the electrode harnessis provided with an electrode, which can be positioned in variouslocations over one of the arms of the harness allow for moreaccurate/reliable data capture. Preferably, the electrode operates on atrack incorporated into the electrode harness over which the electrodecan be moved and operated. Still another feature of the electrodeharness of various embodiments of the present invention is partial orfull shielding of the electrical pathways of the harness from electricalnoise or more importantly from large defibrillator voltages. Stillanother feature of various embodiments of the electrode harness of thepresent invention is the ability to trim electrodes, electricalconnections and/or arms of the electrode harness. Finally, anothersignificant feature of the electrode harness of various embodiments ofthe present invention is the use of an electrode harness containing oneor more dry electrodes.

In one embodiment, the present invention includes an electrode harnessfor physiological monitoring of a subject, the electrode harnesscomprising material operable to interconnect at least two electrodes;and at least two electrode connectors provided on the material whereinthe at least two electrode connectors are non-releasable connectors.

In another embodiment, the present invention includes an electrodeharness for physiological monitoring of a Human (infant through adult)or animal subject, the electrode harness comprising at least twoelectrodes; and material operable to interconnect the at least twoelectrodes; wherein the material comprises at least two expandable arms,each of the at least two arms corresponding to the at least twoelectrodes which are permanently attached to the at least two expandablearms. What about 1 or more expandable arms i.e SLINKY with electrode oneither end.

In still another embodiment, the present invention includes an electrodeharness for physiological monitoring of a subject, the electrode harnesscomprising at least two dry electrodes; and material operable tointerconnect the at least two dry electrodes; wherein the at least twodry electrodes are permanently attached to the material.

In still another embodiment, the present invention includes an electrodeharness for physiological monitoring of a subject, the electrode harnesscomprising at least two dry electrodes each with a releasable connector;and material operable to interconnect the at least two dry electrodeswith at least two mating connectors for the corresponding releasableconnectors.

In still another embodiment, the present invention includes an electrodeharness for physiological monitoring of a subject, the electrode harnesscomprising at least two dry electrodes; material operable tointerconnect the at least two dry electrodes; and at least twocorresponding non-releasable connectors connected to the material.

In still another embodiment, the present invention includes an electrodeharness for physiological monitoring of a subject, the electrode harnesscomprising at least one electrode with adjustable connector; and amaterial operable to interconnect at least two electrodes; and a tracksystem attached or integral to the material wherein the at least oneelectrode is movable along the track system with the adjustableconnector.

In still another embodiment, the present invention includes an electrodeharness for physiological monitoring of a subject, the electrode harnesscomprising at least two electrodes; and a material operable tointerconnect the at least two electrodes wherein the material istrimable to remove one of the at least two electrodes.

In still another embodiment, the present invention includes an electrodeharness for physiological monitoring of a subject, the electrode harnesscomprising at least two electrodes; and a material operable tointerconnect the at least two electrodes, the material comprising atleast two electrical pathways from the at least two electrodes, theelectrical pathway being electrically shielded from large defibrillatorvoltages.

Additional features and advantages of the invention will be set forth inthe detailed description which follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary of theinvention, and are intended to provide an overview or framework forunderstanding the nature and character of the invention as it isclaimed. The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate various embodimentsof the invention and together with the description serve to explain theprinciples and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Schematic view of a subject wearing a biopotential measurementsystem with one embodiment of the electrode harness of the presentinvention.

FIG. 2. a) Schematic view of a subject wearing a biopotentialmeasurement system with another embodiment of the electrode harness ofthe present invention, and b) the electrode harness of FIG. 2 a).

FIG. 3. Schematic view of a subject wearing a biopotential measurementsystem with still another embodiment of the electrode harness of thepresent invention.

FIG. 4. Perspective view of a section from the electrode harness of FIG.3 cut along the line A-A′ of one embodiment of the laminate material forthe track system in FIG. 3, and which further provides for electricalshielding of the electrical pathways of the electrode harness.

FIG. 5. Schematic view of a subject wearing a biopotential measurementsystem with still another embodiment of the electrode harness of thepresent invention.

FIG. 6. a) Perspective view of one embodiment of a track electrode onthe track of certain embodiments of the electrode harness of the presentinvention, and b) a cross-sectional view of such track electrode on thetrack of such electrode harness.

FIG. 7. Perspective view of one embodiment of an expandable arm ofcertain embodiments of the electrode harness of the present invention.

FIG. 8. Perspective view of a non-releasable connector and electrodeused in various embodiments of the present invention.

FIG. 9. a) Exploded view of another embodiment of a non-releasableconnector used in various embodiments of the present invention, and b) across-sectional view of the same.

FIG. 10. Perspective view of a locking connector and electrode used invarious embodiments of the present invention.

FIG. 11. Perspective view of another embodiment of a locking connectorand electrode used in various embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to an electrode harness and moreparticularly to an electrode harness with various features, whichenhance the use and performance of the electrode harness. The presentinvention further relates to a method of taking a physiological orpreferably a biopotential measurement.

The various embodiments of the electrode harness and methods of thepresent invention allow for use with most applications wherebiopotential or physiological measurements are taken. The electrodeharness of the present invention is preferably used for sensing ordetecting a physiological or biopotential signal from a subject. Thesubject from which a physiological signal is measured being a human orother form of animal. The electrode harness can be used in a variety ofapplications including but not limited to electrocardiography (ECG),electroencephalography (EEG), electrical impedance tomography (EIT),electromyography (EMG), electro-oculography (EOG) and Bio-electricalimpedance (BIA), biopotential or physiological measurement applications.Because of the versatility of various embodiments of the presentinvention, preferably the electrode harness can be adjusted fordifferent applications or for application to various sized and shapedsubjects. The electrode harness is further preferably part of a system,which includes either wireless or tethered bridges between the electrodeharness and a monitor, and preferably includes various forms ofprocessors for analyzing the biopotential signal. The electrode harnessof the present invention further allows for greater improvement in homehealth care monitoring systems.

The electrode harness of the present invention preferably comprises amaterial operable to interconnect at least two electrodes. Morepreferably, the material is formed from a multi-layer laminate. Thematerial of the electrode harness of the present invention interconnectsat least two electrodes by preferably providing separate electricalpathways to each of the electrodes. These materials can be processed byany means known to those skilled in the art. Preferable methods includesilk screening or photo-resist processes where electrical traces areformed on or incorporated in various layers of the laminate.

Once the appropriate electrical pathways or traces are formed on one ormore layers for use in the material of the present invention, themulti-layer laminates can be formed by any of the traditional coatingand conversion processes known to those skilled in the art. Preferably,the conductive layers are joined with other, layers of adhesive,coatings, facestocks and liners to provide a multi-layer laminate withthe appropriate features and/or properties necessary for the specificapplication of the electrode harness. The multi-layer laminates then arepreferably die cut and/or formed into the desired shapes for theseapplications. One example is to provide for a shape, which allows thematerial or arms formed from the material to expand or adjust todifferent subject sizes or body placement locations.

Another example is the formation during the conversion process of amechanical weak point in the material. The mechanical weak point cantake many forms. Preferably, the mechanical weak point is a perforationthrough the material or a scoring of the surface of the material. Themechanical weak point is one preferred feature that allows for a laterchange in the configuration of the electrode harness. Thus, separatingthe electrical pathways and/or electrode leads or arms from one anotherby use of the mechanical weak point, allows for a wider area for whichto place the electrodes. Such configurations enabled by the mechanicalweaknesses would be greater in area then configurations allowable whenthe electrical pathways are permanently configured. Separation of theelectrical pathways from one another in order to more accurately placeindividual electrodes on the skin of the monitored subject allows for awider variety of uses from the same electrode harness. The forcerequired to separate the mechanical weak points in the substrate shouldbe greater than forces normally occurring during use of the electrodeharness. In one embodiment, the mechanical weak point extends from theelectrode connector down through the entirety of the electrical pathway,terminating at the transmitter plug.

In another embodiment, mechanical weak points are created laterallyacross the electrode harness. Lateral mechanical weak points, similarlyto the longitudinal mechanical weak points, are made in the substratematerial and not in the electrical pathways themselves. Mechanical weakpoints across the harness allow for the electrode harness including theelectrical pathways to be severed, thus shortening their length. Anynumber of lateral mechanical weak points can be made at any intervalalong the electrode harness.

Another embodiment of the invention contains a track system forplacement of electrodes. This track system operates in order for theuser to place electrodes at any point along the electrical pathway. Theelectrical pathway is embedded in the substrate. Above the entire lengthof the electrical pathway is a slit in the substrate that allows theuser to electrically connect an electrode connector to the electricalpathway. The slit substantially covers the electrical pathway,protecting it from outside signals or unwanted physical contamination.The electrode connector electrically connects to the electrical pathwayvia a conductive pin or protrusion that when attached to the flexiblesubstrate, passes through the slit in the flexible substrate and restsin contact with the electrical pathway. The conductive pin thereforecreates a pathway for biopotential signals received by the electrode tobe transmitted through the conductive pin to the electrical pathway inthe electrode harness. In another configuration, the electrical pathwayis completely covered by the flexible substrate. However, the substrateis perforated above the electrical pathway allowing the conductive pinon the electrode connector to puncture the perforations and electricallyconnect the electrode to the electrical pathway embedded in thesubstrate. This configuration has the advantage of additional protectionfor the electrical pathway embedded in the substrate.

In still another embodiment, the electrical pathways are electricallyshielded from large defibrillator voltages and smaller voltages, bothwhich would degrade the biopotential signal. The electrical pathwayswithin the flexible substrate are longitudinally enclosed with aconductive layer of shielding, such as metal or foil, extending from theelectrode connector to the output plug at the opposite end of theelectrode harness. Each individual electrical pathway is shielded.

The material of the electrode harness of the present invention, which isoperable to interconnect the electrodes preferably, comprises electrodeconnectors to mechanically and electrically connect the electrodeharness with various types of electrodes. The electrical connectors canbe releasable, lockable, non-releasable or permanent connections.Releasable connectors are those connectors to which electrodes can beconnected or disconnected with little or no effort. Traditional buttontype gel-electrodes use such connectors. The drawback of these types ofconnectors is that sometimes they become inadvertently disconnectedthrough motion of the subject or by external forces on the materials orleads attached to such connectors. In addition, like the disposable orsingle use electrodes, the electrode harness may also be designed orintended to be for one use only. However, if releasable connectors wereto be used, the end user may inadvertently make use of the electrodeharness multiple times thereby undermining the intended performance ofthe harness. Lockable connectors are connectors that can be removed fromthe electrode but only upon the application of forces greater than thosenormally encountered during the application for which the connector isbeing used or where there is some mechanical mechanism, which needs tobe activated or opened in order to release the electrode. Non-releasableconnectors are those connectors, which after attaching to an electrodedo not release the electrode unless the connector is somehow destroyed.Permanent connections are where the electrode is glued, welded, brazedor permanently attached by some means to the material of the electrodeharness. Where connectors are used, the connectors may comprise clips,snaps, and both male and female connectors. The connectors may alsoinclude any other device for mechanically and electrically connectingthe electrode to the electrode harness. Where the electrode harness hasvarious arms, those arms may include one or more electrodes.

The electrodes used with the electrode harness and methods of thepresent invention include but are not limited to gel-type electrodes,dry electrodes, implantable electrodes, and the like. The gel-typeelectrodes and implantable electrodes are known to those skilled in theart. The gel-type electrodes usually comprise a sensing element and aconductive gel for transmitting the signal between the subject's skinand the sensing element. Most preferably, however, dry electrodes areused. The dry electrodes comprising a penetrator for detectingphysiological signals below the surface of the skin as a sensingelement. Dry physiological recording electrodes of the type described inU.S. patent application Ser. No. 09/949,055, which issued into U.S. Pat.No. 6,782,283 on Aug. 24, 2004 are herein incorporated by reference. Dryelectrodes provide the advantage that there is no gel to dry out, noskin to abrade or clean, and that the electrode may be applied in hairyareas such as on an animal or on a male human's chest. Alternatively,the subject(s) skin may be mechanically abraded, or an amplifiedelectrode may be used. Preferably, the at least two electrodes are onesignal electrode and one reference electrode. The at least twoelectrodes don't have to be of the same type, i.e., for example onecould be a conductive gel electrode and the other a dry electrode. Theat least two electrodes can be any shape known to be useful to thoseskilled in the art. For example the electrodes can be circular ornon-circular in shape.

The expandable arm(s) of the present invention in various embodimentspreferably comprises memoryless material, such as materials discussedherein. The expandable arm is die cut or shaped into different types ofpatterns, which allow the arm to be adjusted. Two such shapes are anaccordion or a serpentine pattern. When expanded, a portion or all ofthe expandable arm is extended. Where only a portion of the expandablearm is extended, another portion remains folded or unbroken, or onlypartially unfolded or broken. Pressure on the electrode from thematerial of the electrode harness or arms of the electrode harness ispreferably avoided, providing for a more stable connection of theelectrode to the subject. The expandable arm allows for extension asneeded without extra extension and resulting loose material to betangled or which provides discomfort to the subject. In alternativeembodiments, a stretchable or elastic expandable arm is used. In yetother embodiments, a non-expandable arm is used. In still yet otherembodiments, various combinations of these features are used. In furtherpreferred embodiments, the electrode harness or the arms themselvescomprise spooling or other mechanisms to allow for retraction orexpansion of the arms.

The electrode harness of the present invention is preferably connectedto a tether or a wireless transmitter or transceiver by a leadconnector. A lead connector functions to connect the electrical pathwaysor traces from the material of the electrode harness into the tether orwireless system via a standard electrical configuration. The tether is awired connector to connect the electrode harness to a monitor, processoror other devices, which preferably enables the subject or their healthcare provider to utilize the biopotential signals. The transmitter ortransceiver receives the signals from the electrodes, and comprises aradio, ultrasound, infrared or other transmitter. Preferably, thetransceiver operates according to Bluetooth specifications orcommunications/electronics specifications, i.e., FCC. The transmitter ortransceiver can include but are not limited to various components suchas electrode signal channels, a multiplexer, analog to digitalconverter(s), a controller, a radio, a battery, and the like.Additional, fewer or different components can be used. Adapatable to anybiopotenaital capture system.

In one embodiment, the transmitter is operable to minimize introducingundesired noise or signals. The selected signals are transmitted asradio or other signals modulated with a carrier signal. Various formatscan be used for transmission of signals. Such formats include, but arenot limited to Bluetooth, TCP/IP, or other formats. The controllercontrols the signal acquisition and signals. The transmitted signalscomprise data representing the biopotential signals received from theelectrodes. In alternative embodiments, the controller may also processprior to transmission so that the signals comprise vector data. In oneembodiment, the transmitter also receives control information from thereceiver, such as instructions to resend signals.

The transmitter is positioned near, or attached to, the monitoredsubject. The transmitter may be positioned on the hub, expandable arm,arm juncture, or other position where it may receive signals from theelectrodes. The receiver may be attached to the monitored subjectthrough the use of an appendage band (e.g. arm, leg, wrist, ankle,etc.). The transmitter is provided with a pocket, surface, or beltmount. In alternative embodiments the transmitter can be placed in apocket of clothing, elsewhere on the subject, or in close proximity tothe subject.

In one embodiment, the transmitter is removable from the electricalpathway leading to the electrodes. Clips, plugs, clips, screws, bolts,latches, adhesive, or other devices may be used to releasably connectthe transmitter to the electrical pathway. Electrical contact isprovided by connectors operable to withstand electrical energy producedby a defibrillator. These connectors may also provide the physicalconnection between the transmitter and the electrical pathways mentionedabove. The transmitter is removed for recharging the battery, and/orthere is a mechanism such as a plug used to recharge the battery withoutremoval. The battery or transmitter like the electrode harness and theelectrodes can be used for multiple days or multiple times and isseparately disposable to avoid costly replacement of the entire system.The receiver comprises a radio, infrared, ultrasound or other receiver.An application specific integrated circuit, digital signal processor orother circuit for receiving signals from the transmitter, decoding thereceived signals, and generating representative electrode signals isused. In one embodiment, the receiver comprises a transceiver fortwo-way communication with the transmitter. For example, a transceiveroperable pursuant to the Bluetooth specification is provided.

The radio demodulates the received signals for identifying digital datarepresenting the combined electrode signals. In various embodiments, theradio also includes a modulator for transmitting control information.The controller controls operation of the various components and mayfurther process the signals from the radio, such as interpolating data,converting the signals to digital information, generating controlsignals for the transmitter, operating any user interface, operating anyuser output or input devices, and diagnosing operation of the system.Preferably, the controller in the receiver interpolates the electrodesignals to return the effective sample rate to about 3 kHz or anotherfrequency. This enables the reconstruction filters to have a cutofffrequency many times the bandwidth of the electrode signals, thusminimizing any differences in group delay at the frequencies ofinterest.

With the wireless biopotential monitoring system, the wires from astandard biopotential monitor (e.g. ECG, EEG, etc.) are attached to theconnectors on the wireless receiver. The wires comprise a lead-wire set,cable or electrode connectors from or for the biopotential monitor. Theposts are labeled as electrodes and the wires are connected withcorresponding outputs on the receiver. The receiver outputs signals asif from the corresponding electrodes for processing by the biopotentialmonitor. In alternative embodiments, the receiver includes wires forconnecting with the biopotential monitor.

The biopotential monitor comprises one or more of a bedside monitor, atransport monitor or a discrete (i.e. diagnostic) monitor. Bedside andtransport monitors are used for continuous monitoring, such asassociated with hexaxial-lead monitoring. A discrete monitor typicallyis used periodically for analysis, such as associated with “12-lead”monitoring or obtaining multiple vectors associated with precordialand/or hexaxial leads. The monitor processes the electrode signals as ifthe signals were received directly (hard-wired or tethered) from theelectrodes. Neither the transmitter or receiver includes differentialamplifiers for determining a heart vector associated with twoelectrodes.

Some monitors test for failure or malfunction of electrodes. Forexample, a signal is output on the lead wire to the electrode or adirect current level associated with the signal from which the electrodeis monitored. To continue to provide this functionality, the wirelessbiopotential system tests for electrode failure or malfunction andindicates the results to the monitor. For example, the transmitterperforms the same or similar tests as the monitor. In other embodiments,the transmitter or receiver determines whether the biopotential signalis within an expected range. For example, the controller compares thedigital electrode signals, such as after interpolation, to maximum andminimum thresholds. If either threshold is exceeded by a particularnumber of samples or for a particular time, a lead-off or faultyelectrode is indicated. When one or more samples are subsequently withinhysteresis limits of the thresholds, then an error is no longerindicated. When a lead-off condition is indicated, the receiver opens ananalog switch, or alternatively, does not generate a signal for theoutput corresponding to the malfunctioning or failed electrode. As aresult, the monitor indicates a failure of the electrode. If thetransmitter and receiver are out of radio communication range, alead-off condition is presented to the monitor.

FIG. 1 shows a schematic view of a subject wearing a biopotentialmeasurement system with one embodiment of the electrode harness of thepresent invention. In FIG. 1, the subject 10 is wearing a biopotentialmeasurement system 12. This particular embodiment of the biopotentialmeasurement system 12 comprises a transceiver 14, which is worn by thesubject 10 about the waist 16 by a belt 18. An electrode harness 20 ismechanically connected to the belt 18 via a connector 22. The electrodeharness 20 is further electrically connected via the same connector 22to the belt 18. The belt 18 comprises electrical pathways (not shown),which carry the biopotential signals to the transceiver 14.

In this embodiment, the electrode harness 20 comprises multipleelectrical pathways (not shown) for each of the multiple expandable arms24. In this particular embodiment there are six expandable arms 24. Thematerial 26 of the electrode harness 20 having one or more mechanicalweak points 28 for separation of one or more expandable arms 24 from thebody of the electrode harness 20 or material 26. Each of the expandablearms 24 comprising a lockable connector 30, which can be used to bothmechanically and electrically attach to the electrode 32. The expandablearms 24 and the ability to separate one or more of them from the body ofthe electrode harness 20 allowing for the positioning and connection ofelectrodes 32 in various configurations on a variety of subjects 10.

FIG. 2 shows a schematic view of a subject wearing a biopotentialmeasurement system with another embodiment of the electrode harness ofthe present invention, and the electrode harness of this particularembodiment in more detail. In FIG. 2 a), the subject 10 is wearing abiopotential measurement system 12. This particular embodiment of thebiopotential measurement system 12 comprises a transceiver (not shown),which is worn by the subject 10 about the waist 16 by a belt 18. Anelectrode harness 20 is mechanically connected to the belt 18 via aconnector 22. The electrode harness 20 is further electrically connectedvia a connector (not shown) to the belt 18. The belt 18 compriseselectrical pathways (not shown), which carry the biopotential signals tothe transceiver (not shown). The electrode harness 20 comprises at leasttwo expandable arms 24. In this embodiment, the arms 24 are expandablethrough the use of both flexible materials and the use of accordion typefeatures 34 in the materials to allow users to expand the arms 24 forbetter positioning. The electrode harness 20 further comprises amechanical weak point 36 shown in the call out. The mechanical weakpoint 36 is in the form of perforations 40, which allow the harnessmaterial to be torn 38 allowing for better positioning of the harness20.

FIG. 2 b) is a perspective view of the electrode harness 20 in FIG. 2a). In FIG. 2 b) the electrode harness 20 comprises two arms 24. Thematerial 26 of the electrode harness 20 having one or more mechanicalweak points or perforations 40 for separation of one or more expandablearms 24 from the body of the electrode harness 20 or material 26. Eachof the expandable arms 24 comprising a non-releasable connector 42,which can be used to both mechanically and electrically attach anelectrode or connector/electrode combination 42. The electrode harness20 further comprising a connector 22 for mechanically and electricallyconnecting the electrode harness 20 with the rest of the system (notshown).

FIG. 3 shows a schematic view of a subject wearing a biopotentialmeasurement system with still another embodiment of the electrodeharness of the present invention. In FIG. 3, the subject 10 is wearing abiopotential measurement system 12. This particular embodiment of thebiopotential measurement system 12 comprises a transceiver 14, which isworn by the subject 10 about the waist 16 by a belt 18. The electrodeharness 20 is further comprises a belt 18 for securing the electrodeharness 20 to the subject 10. The electrode harness 20 and belt 18combination comprises electrical pathways 44, which carry thebiopotential signals to the transceiver 14. In this embodiment, theelectrode harness 20 comprises multiple electrical pathways 44 for eachof the multiple arms 46. In this particular embodiment there are fourarms 46. Each of the arms 46 comprising a non-releasable connector 42,which can be used to both mechanically and electrically attach to theelectrode (not shown). This electrode harness 20 also containing a tracksystem shown in call out 48. The track system comprising a track 50 overwhich the connector 42 can be moved to mechanically and electricallyconnect the electrode (not shown) for proper positioning on the subject10. The electrode harness 20 also comprising a marker 51 which can beused to line up the harness with an anatomical feature of the subject 10such as for example the tip of the sternum or some other marker placedon the subject 10. Call out 43 shows the marker 51 as well as a weakness45 in the material to allow for removal of an electrode 42. The boxhousing the transceiver 14 also optionally can further comprise amonitor which tests for electrode failure or malfunction.

FIG. 4 shows a perspective view of a section from the electrode harnessof FIG. 3 cut along the line A-A′ of one embodiment of the laminatematerial 54 for the track system in FIG. 3. This laminate material 54further provides for electrical shielding of the electrical pathways 44of the electrode harness. The laminate material 54 in this particularembodiment comprises four distinct layers. Those being top 56 layer,shielding layer 61 protective layer 60 and an adhesive layer 62. The top56 and other layers 60, 61, 62 forming a track 50 over which theelectrode connector (not shown) can be moved and positioned. While theshielding layer 61 is shown in this embodiment as being positioned oneither side of the electrical pathway 44, it will be understood that inother embodiments the shielding layer may be arranged so as tolongitudinally enclose the electrical pathway 44 with a conductive layerof shielding as noted in the specification above. The shielding layer 61is beneficial as it can be used to prevent electrical interference withthe biopotential signal and/or to prevent large stray currents fromdamaging the system or harming the subject.

FIG. 5 shows a schematic view of a subject wearing a biopotentialmeasurement system with still another embodiment of the electrodeharness of the present invention. In FIG. 5, the subject 10 is wearingan electrode harness 20. The electrode harness 20 in this embodimentcomprises two expandable arms 24 and two arms containing a track system50.

FIG. 6 a) shows a perspective view of one embodiment of a trackelectrode on the track of certain embodiments of the electrode harnessof the present invention, and b) a cross-sectional view of anotherembodiment of a track electrode on the track of such electrode harness.In FIG. 6 a) the track electrode 64 is moveable along the track 50formed by the laminate 54. The track electrode 64 further has aspring-type connector 66, which moves with the electrode 64 along thetrack 50 and keeps the electrode 64 connected with the electricalpathway within the laminate material 54. The cross-sectional view inFIG. 6 b) shows the injection molded case 70 of another embodiment of atrack electrode 64, the spring connector 66, and a dry penetratingelectrode 72. The dry penetrating electrode 72 comprising at least onepenetrator 74 for picking up biopotential signals in the epidermis of asubject's skin.

FIG. 7 shows a perspective view of one embodiment of an expandable armof certain embodiments of the electrode harness of the presentinvention. The expandable arm 24 in FIG. 7 is expandable through the useof both flexible materials and the use of accordion type features 34.The expandable arm 24 has a lockable connector 32, which clips snuglyabout the button 82 of a conventional type gel electrode 80. Theexpandable arm 24 can be used to better position the electrode 80 on thesubject (not shown).

FIG. 8 shows a perspective view of a non-releasable connector andelectrode used in various embodiments of the present invention. Thenon-releasable connector 42 in FIG. 8 comprises a top member 90 with afemale orifice 92 and a bottom member 96 having an upper 98 and a lowersurface 100. The upper surface 98 having a male locking stud 102protruding from the upper surface 98. The male locking stud 102 having asharpened penetrator 64 for piercing the electrode harness (not shown)and locking ribs 66 to prevent release of the connector 42 from theelectrode harness (not shown). The top 90 and bottom 96 members beingattached by a connecting bridge 108. The lower surface 100 of the bottommember 96 comprising a dry electrode 72 with at least one penetrator 74.

FIG. 9 shows an exploded view of another embodiment of a non-releasableconnector used in various embodiments of the present invention, and across-sectional view of the same. The non-releasable connector shown inFIG. 9 a) and b) comprises a lever 120, a shell 122, and a cantilever124. FIG. 9 a) also shows the button connector 82 of a typical gel-typeelectrode (not shown). The button connector 82 further comprises a stud126. When the connector 42 is applied over the stud 126 of the buttonconnector 82, the lever 120 is forced up through the shell 122 andcantilever 124 causing the button connector 82 to be in electricalconnection and locked into place by the connector 42.

FIG. 10 shows a perspective view of a locking connector and electrodeused in various embodiments of the present invention. The lockableconnector 30 shown in FIG. 10 comprises a key hole 130 which allows fora stud 120 from a button connector 82 of a gel-type electrode 80 to beinserted through the connector 30, and a narrowed collar area 132 whichapplies pressure to the neck (not shown) of the stud 120 and effectivelylocks the stud 120 into the connector 30. The key hole 130 also havingan electrical pathway 134 to hold the connecter 30 in electricalconnection with the stud 120 of the button connector 82.

FIG. 11 shows a perspective view of another embodiment of a lockingconnector and electrode used in various embodiments of the presentinvention. The locking, adjustable connector 30 is used to effectivelylock the stud 126 of the button connector 82 into the connector, andthrough the same action and time the connector makes electricalconnection with the lead wire 140 to the connector and cuts off anyexcess wire 142.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention. Thus, itis intended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. An electrode harness for physiological monitoring of a subject, theelectrode harness comprising a. at least one electrode with adjustableconnector; b. a material operable to mechanically and electricallyinterconnect at least two electrodes; c. a track system attached to orintegral to the material wherein the at least one electrode is movablealong the track system with the adjustable connector.
 2. The electrodeharness in claim 1, wherein the material is a multi-layer laminate. 3.The electrode harness in claim 2, wherein the material comprises atleast two expandable arms, each of the at least two expandable armscorresponding to the at least two electrodes.
 4. The electrode harnessin claim 3, wherein the material further comprises a slit or amechanical weak point for separating one of the electrodes.
 5. Theelectrode harness in claim 1, wherein the material comprises at leasttwo expandable aims, each of the at least two expandable armscorresponding to the at least two electrodes.
 6. The electrode harnessin claim 1, wherein the material comprises an electrical pathway fromthe at least one electrode, the electrical pathway being electricallyshielded from large defibrillator voltages.
 7. The electrode harness inclaim 1, further comprising a second electrode wherein the material isreadily separable through created weakness in the material to allow forremoval of one of the electrodes.
 8. The electrode harness in claim 1,wherein the electrode is a dry electrode.
 9. An electrode harness forphysiological monitoring of a subject, the electrode harness comprisingat least two electrodes; a material operable to mechanically andelectrically interconnect the at least two electrodes comprisingseparate electrical pathways to each of the at least two electrodes; anda lead connector to mechanically connect the material and electricallyconnect the separate electrical pathways to each of the at least twoelectrodes of the electrode harness to a tether or a wirelesstransmitter wherein the material is readily separable through aperforation in the material to allow for removal and electricaldisconnection from the lead connector of one of the at least twoelectrodes.
 10. The electrode harness in claim 9, wherein one of the atleast two electrodes is a dry electrode.
 11. The electrode harness inclaim 9, wherein the material is a multi-layer laminate.
 12. Theelectrode harness in claim 11, wherein the material further comprises aslit or a mechanical weak point for separating one of the electrodes.13. The electrode harness in claim 11, wherein the electrical pathwayfrom at least one electrode is electrically shielded from largedefibrillator voltages.
 14. The electrode harness in claim 9, furthercomprising a track system attached or integral to the material whereinone of the at least two electrodes is movable along the track systemwith a connector.
 15. The electrode harness in claim 9, furthercomprising a transmitter, the transmitter being a wireless transmitteroperating according to Bluetooth specifications.
 16. The electrodeharness in claim 9, further comprising a transmitter, the transmitterminimizing undesired noise or signals.